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May 5, l964 G. wlLKE ETAI. 3,132,155

cARBoxyLIc AcID ANHYDRIDES, cARBoxYLIc AcIDs AND cARBoxYLIc AcID EsTERs 0F THE: cYcLoDoDEcANE SERIES,4 AND A PRocDss FOR THEIR PRODUCTION Filed Dec. 17. 1958 United States Patent O M CARBOXYLIC ACID ANHYDRIDES, CARBOXYLIC ACIDS AND CARBXYLIC ACID ESTERS F THE CYCLODODECANE SERIES, AND A PROC- ESS FOR TIIElR PRODUCTON Gnther Wilke, Mulheim (Ruhr), and Werner PfohLHamburg, Germany, assignors to Studiengesellschaft Kohle m.b.H., Mulheim (Ruhr), Germany, a body corporate of Germany Filed Dec. 17, 1958, Ser. No. 780,921 Claims priority, application Germany Dec. 23, 1957 1l Claims. (Cl. Zeil-346.3)

This invention relates to carboxylic acid anhydrides, carboxylic acids and carboxylic acid esters of the cyclododecane series, and a process for their production.

Belgian patent specication Nos. 555,180 and 564,175 disclose processes for the production of cyclododecatri- (1,5,9)enes and also other cyclic hydrocarbons having at least 8 carbon atoms and at least two double bonds in the ring, by the reaction of butadi-(l,3)-ene or its monomethyl substitution products with catalysts. Cyclododecatri-(l,5,9)-enes can also be transposed to trivinyl cyclohexanes. Because of the three double bonds in the molecule, cyclododecatrienes and also trivinyl cyclohexanes constitute reactive compounds which can be used for many additional conversions to provide valuable products.

According to the present invention, carboxylic acid an- `hydrides, carboxylic acids and/or theiresters may be obtained by the addition of l molecule of a cyclododecatri- (l,5,9)-ene or a trivinyl cyclohexane to l-4 molecules of .maleic acid anhydride. The reaction products obtained in the iirst stage of the process according to the invention are` anhydrides of dicarboxylic or higher polycarboxylic acids. The structure thereof is still not known with certainty, but in the products ofthe process according to the invention dicarboxylic or higher polycarboxylic acid anhydrides or formulae as shown in the accompanyingdrawingls must be present,` possibly in admixture with one anot er.

The anhydrides obtained can be converted by saponication into carboxylic acids or by esteritication into carboxylic acid-esters. The properties of the products depend to a great extent on the number of the acid groups present, which can be varied from 2 to 6 or 8, and on the constitution of the alcohols used for esteriication purposes. Thus for example, according to the process of the invention, derivatives of cyclododecatri-(l,5,9)ene with three succinic acid anhydridegroups on the ring can be obtained inva practically quantitative yield, which deriva- 'tives can be transformed by saponifcation into hexacarboxylic acids or by esterication into hexaesters.

Whilst it is true that it is known per se to add olenes to maleic acid anhydride, it was nevertheless not to be lanticipated that the triolefines to be used with maleic acid anhydride, according to the invention would yield anhydrides or dicarboxylic, tetracarboxylic, hexacarboxylic and even octacarboxylic acids by assemblage. This was not to be anticipated, because it has already been established that under the inlluence of various reagents, and more especially of acidly acting substances, cyclododeca- -t ri-(l,5,9)enes are isomerized with the disappearance of the double bonds and also because, as has already been found, trivinyl cyclohexane is unstable under similar conditions. 4

The reaction products' contain novel atom groupings, Afrom which novel and valuable possibilities of use stem. It is 'especially important and advantageous that the properties of the products which can be produced by the Vprocess of the invention can be varied infmany different Way's by `suitablechoice of the reaction conditions and the proportions of the reagents.

The products `with for t JZ, 155 Patented May 5, l 964 ICC example 1 molecule of maleic acid anhydride contain the two originally present double bonds in addition to the double bond adjacent the acid anhydride grouping, no variation in the reactivity havingoccurred in the vicinity of the said double bonds originally present due to the occurrence of a succinic acid anhydride radical. The addition products with more than l molecule of maleic acid anhydride, and more especially those with 3 molecules of maleic acid anhydride, have an interesting spider-like structure and, on esterication, give polycarboxylic acid esters which have very valuable properties as plasticisers. The hexacarboxylic acids which may be obtained from the hexacarboxylic acid anhydrides by boiling with water are soluble in water. This is a remarkable property for acids of such high molecular weight.

t In carrying out the process of the invention, temperatures of from to 250 C., and advantageously of from 150 to 200 C., are employed. The reaction can be effected simply by heating the undiluted reactants, but the cornponents are preferably diluted with a solvent in order to keep the viscosity of the mixture low, especially towards the end of the reaction. Suitable solvents are all those which are inert with respect to maleic acid anhydride, and more especially aromatic hydrocarbons such as benzene, toluene, and xylene, since the products which are formed then remain in solution. When adding a solvent, it is necessary to work in an autoclave.

The course of the reaction according to the invention can be controlled by variousmeasures. For example, 1:1-addition products are advantageously obtained by using an excess of trioleiine, and 1:3-addition products are obtained withan excess of maleic acid anhydride, for example, in order to produce the treble addition product of cyclododecatri(1,5,9)ene, a molar ratio between triolefine and anhydride such as 1:6 to 1:7 is used, and on the other hand, in order to obtain the lzl-addition product of trivinylcyclohexane, for example, a molar ratio between trioletine and anhydride such as 2:1 is used.

However, different reaction products can be obtained by varying the reaction time. In this case, it is expedient to use the maleic acid `anhydride in excess and to take samples from the reaction mixture at intervals, from which samples the maleic acidanhydride and any olene ystill unreacted are distilled olf, whereupon the saponification number of the residue which remains is determined. The table in Example 1 shows how the composition of the reaction product depends on the reaction time.

As has already been statedabove, all products obtained :by the process still contain double bonds as well as the 'acid anhydride groupings. This can be particularly advantageous if the products produced according to the process of the invention are reacted with other suitable substances, for example for the purpose of manufacturing synthetic resins, because in that event additional opportunities for varying the properties of the synthetic resin arise from the presence of the double bonds. The double bonds can of course also be hydrogenated, and in this case saturated dicarboxylic or higher polycarboxylic acid anhydrides are obtained, and there may be hydrolyzed to the corresponding-dicarboxylic or higher polycarboxylic acids, which anhydrides and acids are dis'- 'Vtinguishedby a particularly high resistance to secondary modifications, such as oxidation, because of the absence of Ithe double bonds. l

The following examples further illustrate the invention:

EXAMPLE 1 i 363 g. of maleic acid anhydride and 106 g. of cyclododeca-tri-(l,5,9)ene (molar ratio 5.65 :1) in 600 g. of "benzene are heated in a 2-litre V2A-autoclave equipped with magnetic stirring means and heating means. Samples are removed after certain time intervals. The heating period, temperature and analysis of the intermediate products are shown in the following table. Analysis of the samples is so carried out that maleic acid anhydride, benzene and olefine are distilled oli in vacuo andthe saponiiication number of the residue is determined.

tion number of 720 (theoretical 737) and oxygen content of 31.52% (theoretical 31.56% O), to a 1:3-addition product cyclododeca-tri-(l,5,9)eneemaleic acid anhydride.

With `increasing reaction times,'the colouring of the samples becomes somewhat more intensive. Sample 1 has a light yellow colour, while sample 4 is brown in colour. Samples l to 4 are soluble in alcohol. Sample 4, after saponication, is also completely solublein cold and hot water. The yield of 1:3-addition product is practically quantitative.

EXAMPLE 2 135 g. of maleic acid anhydride and 30 g. of cyclododeca-tri(l,5,9)ene (molar ratio 7.711) in 110 g. of benzene are heated for 14 hours at 195 to 200 C. in a 500cc. V2A-autoclave. The mixture is then cooled to below the boiling temperature of benzene and the brown reaction medium is removed and placed in a distillation flask. 'The benzene is distilled oit at normal pressure and the excess maleicV acid anhydride iny vacuo. The last'traces of maleic acid anhydride are distilled ounder 'high vacuum. 82.5 g. of a brown brittle product whichis viscous at 110 C. and resinous at room temperature are ofthe 1:1-addition product is 87.5%. lThe elementary analysis and the saponication number correspond to those of the 1:1-addition product.

Catalytic hydrogenartion in the presence of Raney nickel, whereby a satunated dicarboxylic acid anhydride is domed, reveals the presence of three double bonds per molecule.

The benzene Aand the mixture of mlaleic acid anhydride and cyelododecatriene distilled .oil from the solution discharged trorn the autoclave as descnibed above, are again introduced into the reaction and, under the same conditions as described above, further 1:1-addition product yis obtained.

EXAMPLE 4 12 g; of maleic acid anhydride and 32 g. of trivinyl distilled oil under high vacuum. its elementary analysis obtained. The yield is 97% of the theoretical.` The saponication numberis 712 (theoretical 737). The end product has the following composition; C=63.30% (theoretical 63.15%), H=5.35% (theoretical 5.3%), 0=3l.42% (theoretical 31.56%).

The triple succinic acid anhydride addition product is saponi'ed conventionally, for example with water or aqueous alkali, and the saponication solution is in the latter event freed from alkali metal ions by an acid ion exchanger. ln thisY way, a clear aqueous solution of hexacarboxylic acid is obtained.

The ethyl ester is prepared in the following manner: 10 g. of the product with 45 cc. of ethanol and 45 cc. of

benzene, and with the addition of 047 g. of p-toluene sulphonic acid, are heated for 3 days to boiling point under a fractionating column; the water'formed is removed byazeotropic distillation. The mixture obtained by esterication is taken up in ether to remove the acid and is washed with water. After dryingthe ether solution and distilling oil the solvent, a viscous brown residue Yis left; it has an ethoxyl content of 37.7% (theoretical for the hexaester is 39.93%

EXAMPLE f3 r`at 160 C. and for 35 hours at 170 C. After cooling the autoclave, a clear slightly yellowish solution is discharged. The benzene, and excess maleic acid anhydride and cyclododecatri(l,5,9)ene are distilledoil and the residue dis- Vtilled under high vacuum. At aboiling temperature of to 130 C., 21g. of a highly viscous colourless substance are obtained. 3 g. of va brownish-yellow, resinous, brlttle product arevleft as undistillable residue. The yield and saponiiication number confoi'rn to those of the 1:1- addition product. The yield of the lil-addition product EXAMPLE 5 g. of maleic lacid anhydride and 31 g. of trivinyl cyclohexane (molar ratio 7:1) lin 130 g. of benzene are heated in a 500 cc. V2A-autoclave for 30 hours at 150 to 155 C. and for a further `8 hours at 155 to 160 C. A clear -solution is obtained, in which 4a solid yellow substance is suspended. On Workingvup, 80 g. of a yellow brittle resinous product are obtained, the sapom'cation number of which is 830 (theoretical, 809.5) and the oxygen value of which is 34.95% (theoretical, 34.62%), corresponding tov a 4:1-addition product of maleic acid anhydride 1with trivinyl cyclohexane. The substance can readily be hydrolyzed and the hydrolysis Yproduct is completely soluble in water.

v.exznvrPLE 6 The procedure of Example `2 is followed, ybut toluene or xylene is used as the solvent instead of benzene. After the reaction with maleic acid anhydride and the removal of the solvent, the triple addition product of maleic acid anhydride with cyclododecatri-(1,5,9)ene is obtained in the yield indicated in Example 2.

EXAMPLE `7 l lThe esterication of @the triple addition product of maleic facid anhydride with cyclododeoatri(1,5,9)ene is carried out as follows:

10 g. `of the addition product are heated in twice the `v'stoichiornetric quantity of the corresponding alcohol in .added to the reaction mixture that the temperature was maintained a-t C. with strong reilux. The reaction is completed when no more Water is separated out in the phase separation head. 'The reaction mixture is then washed with water and caustic soda solution in order -to remove the acid added from esteriiication purposes. The dried solution is freed by distillation from solvent and excess-alcohol. the residue. Y

YBy using hexan-l-ol as the alcohol, the hexahexyl esterV of the S11-addition product was obtained, saponication number`293.

'Ilhe `desired ester is obtained as By using tetradecan-l-ol as the alcohol, the hexatetradecyl ester was obtained, saponiiication number 169.

By using butan-l-ol as'the alcohol, the hexabutylester was obtained, saponication number 356.

What we claim is: i

1. A process comprising reactingv :at an elevated rternperature from 1-4 molecules of maleic" acid anhydride with one molecule of a triolene which is a member selected from the group consisting of cyclododeca-tri- (1,5,9)ene and trivinyl cyclohexane and recovering the reaction productrther'eby formed.

2. Process according reclaim 1 which comprises eflfecting said reactionat a temperature of between 150 and 250 C.

3.l lPnocess according to claim. 2 which comprises effecting said reaction at a Iltemperature of between 150 and 200 C.

4. Pr'ocess according to claim 1 which comprises effecting said reaction Iin fthe presence of a solvent which is inert with respect to maleieacid anhydride.

5. Process according'to claim 4 wherein said solvent is an aromatic hydrocarbon.

6. Process according to claim 5 wherein said aromatic Y hydrocarbon is a member selected irorn the group consisting of benzene, toluene and Xylene.

7. Process according to claim 1 which comprises employing an excess of said triolene with respect to said maleic `acid anhydride and wherein said reaction product formedvis a product in which one molecule of maleic acid anhydride has been added to one molecule of niolene. 8. Process according to claim 1 which comprises employingan excess of said maleic acid anhydride with respect to said trioleine and Where said reaction product formed is a product in 'which three molecules of maileic acid anhydride have been added to one molecule of Irivoleine.

9. Process according to claim 1 which comprises hydrolizin-g the carboxylic acid anhydride which is formed and recovering the corresponding carboxylic acid.

10. ProcessV according \to claim 1 which comprises esterify-ng the carboxylic acid formed with Ian alcohol.

11. A member selected fnom the group of carboxylic acid anhydrides having the following formulae:

20 and References Cited in the file of this patent Doolittle: The Technology of Solvents and Plasticizers, pages 862-8 (1954).

Bnttrey: Plasticizers (second edition, 1957), page 8. Glassication Manual, Class 260 (April 1958), pages UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. May 5 1964 Gnther Wilke et al.

It is hereby certifiedthat error appears in the above numbered patent requiring correction and thatA the said Letters Patent should read as y corrected below.

Column 4, line 69, for "from" read for column 5, line 34, for "where" read wherein column 6, lines 5 to l9, the formula should appear as shown below'instead of as in the patent:

Signed and sealed this 13th day of October 19.64.

EDWARD J. BRENNER Commissioner of Patents RNESTy W. SWIDER Lttesting Officer 

1. A PROCESS COMPRISING REACTING AT AN ELEVATED TEMPERATURE FROM 1-4 MOLECULES OF MALEIC ACID ANHYDRIDE WITH ONE MOLECULE OF A TRIOLEFINE WHICH IS A MEMBER SELECTED FROM THE GROUP CONSISTING OF CYCLODODECA-TRI(1,5,9)-ENE AND TRIVINYL CYCLOHEXANE AND RECOVERING THE REACTION PRODUCT THEREBY FORMED.
 11. A MEMBER SELECTED FROM THE GROUP OF CARBOXYLIC ACID ANHYDRIDES HAVING THE FOLLOWING FORMULAE: 